CLEANING EQUIPMENT FOR CONVEYOR BELTS

Abstract: There is disclosed cleaning equipment for use in cleaning a moving conveyor belt, the equipment comprising a plurality of concave plates (26) mounted for rotation about an axis (24), and holding means (27, 28 and 29) for holding the plates (26) with the axis (24) at an inclined angle with regard to the line of movement (23) of the conveyor belt with the concave face of the plates (26) facing the oncoming conveyor belt and with the plates (26) contacting the conveyor belt so that the plates (26) are caused to rotate about the axis (24) by movement of the conveyor belt. The equipment provides effective cleaning with minimal wear of the belt or the plates.

Description: CLEANING EQUIPMENT FOR CONVEYOR BELTS This invention relates to cleaning equipment for use in cleaning a moving conveyor belt. When conveyor belts carry certain material, not all of the material is thrown clear of the conveyor belt as the belt moves around one of the end pulleys, and the purpose of the cleaning equipment of the present invention is to remove any material which remains adhering to the belt just downstream of the normal discharging point from the belt, so that the belt travelling back to the loading point is relatively clean. According to a first aspect of the present invention, there is provided cleaning equipment for use in cleaning a moving conveyor belt, the equipment comprising a plurality of concave plates mounted for rotation about an axis, and holding means for holding the plates with the axis at an inclined angle with regard to the line of movement of the conveyor belt with the concave face of the plates facing the oncoming conveyor belt and with the plates contacting the conveyor belt so that the plates are caused to rotate about the axis by movement of the conveyor belt. Conveniently the plates are mounted on an axle, with provision for the plates to rotate with respect to the axle or with provision for the whole axle and the plates mounted on the axle to rotate. Preferably the equipment comprises two sets of concave plates each mounted on a respective axle, with the axles inclined to each other, but with the concave faces of the plates facing the oncoming conveyor belt, and with one set of plates clearing half the width of the conveyor belt and with the other set clearing the other half. The mounting of the two sets of plates in a V relationship is to reduce the tendency of the conveyor belt to be thrown to one side, which is more likely to occur if all of the plates were mounted on just one axle extending all of the way across the belt. The distance between adjacent plates on the axle can be varied to suit cleaning conditions and, in particular, the nature of the material to be cleaned, but is often in the range from 3 to 4 cm. The angle of inclination of the axis of the plates to the line of movement of the conveyor belt can be varied depending on the nature of the material being removed. Instead of the axis being perpendicular to the line of movement of the belt, the axis is moved through a minimum of 5 to 10°, up to a maximum of 45°, but typically, for example, 22° so as to cause the concave face of the plates to face the oncoming belt. The diameter of the plates can vary according to the choice of material being used, but could be, for example, 22cm, and the degree of "dishing" of the dish plates could be 25mm. Where two axles are held in an inclined relationship with all of their concave plates facing the oncoming belt, there can be a region not adequately cleared by the plates, corresponding to the position where the two axles are mounted adjacent each other in a suitable mounting arrangement. In this case the cleaning equipment can additionally include rubber blocks mounted upstream of the axles, which blocks are used to deflect material on the belt from the zone which otherwise would not be swept clear, and into regions which will be cleaned by the plates. An alternative arrangement is that wherein one axle is mounted slightly further upstream than the other axle and the two end regions of the axles overlap. The holding means preferably has some spring loading so as to urge the plates or deflectors firmly towards the conveyor belt, but with some resilience, to allow some degree of take up where the material being removed is particularly problematical. Preferably the concave plates are freely mounted on the axle or axles with provision for spacers of different lengths to be positioned between the plates whereby the spacing between the plates can be varied. The equipment preferably also comprises means for adjusting the angle of the axle relative to the direction of movement of the conveyor belt. It is of importance that the plates are concave but, if necessary, a large central region of the plate can be planar, with only the outermost region, e.g. 6cm, as measured in the radial direction, being concave. The plates may be formed of any convenient material, for example a mild steel or rubber. According to a second aspect of the present invention, there is provided conveyor belt equipment which includes a movable conveyor belt and which is provided, adjacent the conveyor belt in a location downstream of the usual discharge point, with cleaning equipment according to the first-mentioned aspect of the present invention. In many applications of the conveyor belt equipment, about 99% of the material being conveyed by the conveyor belt falls from the belt at the usual discharge point into a collection bin. The remaining 1% or so can then be substantially completely removed from the belt by the cleaning equipment of the first mentioned aspect of the present invention. To avoid loss of material, the conveyor belt equipment of the second-mentioned aspect of the present invention can also include an additional conveyor belt located below the cleaning equipment and positioned so as to convey material removed form the first-mentioned belt by the cleaning equipment to the collection bin. The additional conveyor belt can be powered separately from the main belt or can be powered by a pulley associated with the main belt, and can travel more slowly than the main belt as it has less material to convey. If desired the additional conveyor belt may contact the main conveyor belt downstream of the cleaning equipment to help dislodge any material still adhering to the main belt. The additional conveyor belt may be formed of any suitable material, and could, for instance, be a spiked rubber belt. The conveyor belt equipment of the second- mentioned aspect of the present invention could additionally include a vacuum head located adjacent the main belt and downstream of the cleaning equipment, to assist in the removal of dust. A yet further conveyor belt may be located downstream (in terms of travel of the main belt) of the cleaning equipment of the first-mentioned aspect and may move in the opposite direction to, and lightly brush against, the main belt. The cleaning equipment of the present invention can provide effective cleaning with only minimal wear of the conveyor belt and the concave plates which contact the belt. For a better understanding of the present invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which:- Figure 1 is a schematic side view of conveyor belt equipment in accordance with the present invention; Figure 2 is a view of part of a conveyor belt frame, with the conveyor belt removed, taken from above, showing cleaning equipment in accordance with the present invention; Figure 3 is a side view of part of the equipment shown in Figure 2, with the conveyor belt in position; Figure 4 is a view, mainly from above, but partly from the side, of part of the cleaning equipment of another embodiment of the present invention; Figure 5 is a side view of conveyor belt equipment; and Figure 6 is a side view of one of the dished plates abutting the conveyor belt. Referring firstly to Figure 1, there is shown an end roller 1 of a conventional conveyor belt arrangement, on which roller 1 is supported a conveyor belt 2, the upper run of which is moving to the left in Figure 1, with the lower run returning to the right. Indicated by the arrow 3 is the position at which most material carried by the belt 2 is discharged from that belt and falls into a collection in 4. Shown as a block 5 is the cleaning equipment in accordance with the present invention, positioned against the underside of the lower run of the belt 2. Material removed by the cleaning equipment 5 falls from that equipment onto an additional conveyor belt 6 which is supported by its own end rollers 7 and 8. The conveyor belt 6 is powered either by its own power unit or by a drive from the end pulley 1. Downstream of the cleaning equipment 5 and located also adjacent the underside of the lower run of the conveyor belt 2 is a vacuum head which can be useful in assisting in the removal of any dust still adhering to the underside of the lower run of the belt 2, particularly in dry conditions. The dust can be disposed of on the upper run of the additional conveyor belt 6 or can be conveyed directly to the collection bin 4. In addition, there may be a further conveyor belt 10 being driven around its respective end rollers 11, 12 and 13, with the upper run of the further conveyor belt 10 lightly abutting and moving in the opposite direction to the lower run of the main conveyor belt 2. The further conveyor belt 10 can run continuously slowly or run intermittently with short breaks. In an alternative arrangement, the additional and further conveyor belts 6 and 10 could be replaced by a single, longer belt, with the end pulleys 8 and 11 being replaced by a single pulley, the single belt nonetheless performing the same function as the two belts 6 and 10 shown in Figure 1. With regard to Figure 2, there is shown part of a frame generally indicated by the numeral 20. The frame 20 forms part of a conveyor belt equipment and it includes longitudinally extending frame members 21A to 21D as well as transverse frame members 22A and 22B. Although the belt is not shown in Figure 2, the arrow 23 indicates the direction of movement of the belt when present. Resiliently mounted with respect to the frame members 21B and 21C are two rollers 24, which are disposed in a V-formation. Only one axle 24 is shown, the other axle 24 being masked by a freely rotatable roller 25 which carries a plurality of dished plates 26. The axles 24 are mounted by spring-loaded mountings 27 and 28 with regard to the frames 21C and 21B, respectively, and are also located at their near most end regions with respect to a central spring- loaded mounting 29. The arrangement is such that when the conveyor belt is present the plates 26 are resiliently urged firmly against the belt 25 and the plates 26 are caused to rotate by the movement of the conveyor belt. The rotation assists in the cleaning movement and also clears away the material picked up by the plates 26. Part of the equipment shown in Figure 2 from above, is shown as a side view in Figure 3. Figure 4 shows a different embodiment of the cleaning equipment. Figure 4 shows an alternative arrangement to that shown in Figures 2 and 3, bur the same principle applies. In Figure 4 there are two inclined axles 30 and 31, the axle 30 carrying a plurality of part spherical plates 32, and the axle 31 carrying a plurality of partly spherical plates 33. The axle 30 at one end is mounted for free rotation at one resiliently fixable mounting point 34 and at its opposite end to a mounting point 35. The other axle 31 is mounted at one end with a resiliently flexible mounting arrangement 36 and at its other end is mounted for free rotation at a resiliently flexible mounting arrangement 37, which can be regarded as another part of the mounting 35. It can be appreciated that the plates 32 and 33 have a convex face and a concave face. The equipment is aligned relative to the intended direction of movement of the belt such that the concave faces meet the oncoming belt. It will be appreciated that a central region of the belt may not be swept clean by the plates 32 and 33 and, for this reason, three stationary rubber blocks (shown in elevation) are located to deflect material on the belt into the face of the plates 32 and 33. Figure 5 shows a typical arrangement of a conveyor belt with material being deposited on a lower end of the belt and being conveyed upwardly by the belt and discharged at the upper end indicated. Position 39 is the optimum place for locating the cleaning equipment in accordance with the present invention. Figure 6 is a section through one of the plates 32. The plate 32 is abutting a belt 40 and material 41 on the belt 40 is caught in the concave face of the plate 32.

Claims: CLAIMS 1. Cleaning equipment for use in cleaning a moving conveyor belt, the equipment comprising a plurality of concave plates mounted for rotation about an axis, and holding means for holding the plates with the axis at an inclined angle with regard to the line of movement of the conveyor belt with the concave face of the plates facing the oncoming conveyor belt and with the plates contacting the conveyor belt so that the plates are caused to rotate about the axis by movement of the conveyor belt. 2. Cleaning equipment according to Claim 1, wherein the plates are mounted on an axle, with provision for the plates to rotate with respect to the axle or with provision for the whole axle and the plates mounted on the axle to rotate. 3. Cleaning equipment according to Claim 2, wherein the equipment comprises two sets of concave plates each mounted on a respective axle, with the axles inclined to each other, but with the concave faces of the plates facing the oncoming conveyor belt, and with one set of plates clearing up to half the width of the conveyor belt and with the other set clearing at least the majority of the other half of the belt. 4. Cleaning equipment according to Claim 3, in which the two axles are held in an inclined relationship but in which there is a region not adequately cleared by the plates, corresponding to the position where the two axles are mounted adjacent each other in a suitable mounting arrangement, wherein the cleaning equipment additionally includes rubber blocks mounted upstream of the axles, which blocks are used to deflect material on the belt from the zone which otherwise would not be swept clear, and into regions which will be cleaned by the plates. 5. Cleaning equipment according to claim 3, wherein one axle is mounted slightly further upstream than the other axle and the two end regions of the axles overlap. 6. Cleaning equipment according to any one of claims 2 to 5, wherein the distance between adjacent plates on the or each axle is in the range from 3 to 4 cm. 7. Cleaning equipment according to any preceding claim, wherein the angle of inclination of the axis of the plates to the line of movement of the conveyor belt is in the range from 45" to 80° or 85°. 8. Cleaning equipment according to any preceding claim, wherein the diameter of the plates is approximately 22cm, and the degree of "dishing" of the concave plates is approximately 25mm. 9. Cleaning equipment according to any preceding claim, wherein the holding means has some spring loading so as to urge the plates firmly towards the conveyor belt, but with some resilience, to allow some degree of take up where the material being removed is particularly problematical. 10. Cleaning equipment according to any one of claims 2 to 6 or to any one of claims 7 to 9 when appendant to claim 2, wherein the concave plates are freely mounted on the axle or axles with provision for spacers of different lengths to be positioned between the plates whereby the spacing between the plates can be varied. 11. Cleaning equipment according to any preceding claim, which includes means for adjusting the angle of the axis relative to the direction of movement of the conveyor belt. 12. Cleaning equipment according to any preceding claim, wherein the plates " are formed a mild steel or rubber. 13. Conveyor belt equipment which includes a movable conveyor belt and which is provided, adjacent the conveyor belt in a location downstream of the usual discharge point, with cleaning equipment according to any one of Claims 1 to 12. 14. Conveyor belt equipment according to claim 13, which also includes an additional conveyor belt located below the cleaning equipment and positioned so as to convey material removed form the first-mentioned belt by the cleaning equipment to a collection bin. 15. Conveyor belt equipment according to claim 14, in which the additional conveyor belt or a yet further conveyor belt contacts the main conveyor belt downstream of the cleaning equipment to help dislodge any material still adhering to the main belt. 16. Conveyor belt equipment according to claim 14 or 15, wherein the additional conveyor belt is a spiked rubber belt. 17. Conveyor belt equipment according to claim 13, 14, 15 or 16, which additionally includes a vacuum head located adjacent the main belt and downstream of the cleaning equipment, to assist in the removal of dust.

Inventors: VOWLES ASHLEY DENNIS, VOWLES, ASHLEY, DENNIS
Applicants: VOWLES ASHLEY DENNIS, VOWLES, ASHLEY, DENNIS
Application year: 1994
Main classification: B65G45
IPC codes: B65G45